CSS Code changes to Price structure using the Prestige Theme

[Chairman_1]

Hi there,  I am new to Shopify with our Chairtrader.com shop.  We wish to show the RRP as well as the Discounted Price as well as the VAT element.  I understand that I need to change the CSS Code but am not sure exactly where to do this.  We are using the Prestige Theme.

Any advice would be much appreciated.

Many thanks,

David